Vic Viner, thought to be the sole survivor of the navy's rescue operation at Dunkirk, will take part in the flotilla on board one of the 'little ships'. Photograph: Martin Godwin

As Olympian rowing knights Steve Redgrave and Matthew Pinsent take up their oars on the Gloriana barge at the head of Sunday's 1,000-vessel Thames flotilla, Lieutenant Will Dixon, 28, will be settling in alongside them.

The former platoon commander with the 3rd Battalion, The Rifles, who lost his left leg below the knee to a roadside bomb in Afghanistan in 2009, is no stranger to life on the water. With three other military service personnel who have suffered life-changing injuries, he successfully rowed 3,000 miles across the Atlantic last year as part of the fundraising Row2Recovery team. Now all four will join members of the Paralympic rowing squad as part of a unit of 18 oarsmen powering the newly built royal barge.

They are among a group of extraordinary individuals who, using the national spotlight on this weekend's celebrations, hope to champion a variety of causes and bequeath to the diamond jubilee commemoration a legacy that will last long after the bunting and flags have been taken down.

"Just hearing some of the stories of the people involved in the celebrations, at all levels, is incredible," said Dixon, who took up the Row2Recovery challenge to "redefine" himself as "the guy that rowed the Atlantic, rather than the injured soldier".

He and his fellow rowers are motivated by "the idea of sending a positive message not just to other injured soldiers but in terms of disability in general". Now working for a bank in London, Dixon sees the jubilee celebrations as an opportunity to "make us look at ourselves as a country and at all the positive messages we have got.

"I think with the Gloriana, the way the crew has been put together and the guests on board is great and conveys a really strong, inspirational message, I hope," he said.

The 12 disabled people on board the Gloriana, as oarsmen or passengers, were invited to take part by the charity Motability. They will also include Major Kate Philp, 33, who lost her left leg when her Warrior tank ran over a 50kg Taliban bomb in Afghanistan. British Paralympic swimmers Sascha and Nyree Kindred are also guests.

Further back in the flotilla, with his campaign medals pinned to his chest, will be Vic Viner, at 95 believed to be the oldest participant. Viner, from Dorking, Surrey, is thought to be the sole survivor of the Royal Navy's 156-strong rescue operation at Dunkirk. Appropriately, he will be aboard the Jacantha, one of the Dunkirk "little ships".

Memories of those terrible days remain undimmed for Viner. Having landed on the French coast from the destroyer HMS Esk, his immediate task was to row to the beach, pick up soldiers, and bring them back to the destroyers. "If you can imagine picking up 15 soldiers complete with all their kit, it was pretty heavy going. When we got back to the ship on the fourth trip, my colleague said: 'Vic, you've got blood all over your hands'. You've heard the expression to sweat blood. Well, we were, literally, sweating blood".

When Operation Dynamo began, Viner found himself on the beach loading desperate, stranded soldiers into the little ships, "getting them into columns and getting them on board", while being constantly dive-bombed.

"You've got men who'd been walking for four or five days. Some were completely shattered. The Blitzkrieg had started. They just didn't know what had hit them. They were fighting tanks with rifles. It's very hard to describe what state they were in," he recalled.

At one point he was blown into the water by a Stuka's bomb, regaining consciousness to find his tin helmet and trousers were still on, but that his jacket had been blown off.

Viner, who gives talks to schools and clubs about his wartime experiences, said being invited to take part in the pageant "was a very great honour: it is very historic and of course I'm very excited. I will hopefully have fantastic memories of the day."

Many of those participating have overcome adversity, or have committed themselves to helping others do so.

Breast cancer survivors will be taking to dragon boats. The Row for Freedom female crew, which crossed the Atlantic in support of two charities fighting human trafficking, will also be there. In the recreational motor boats section, the Wally Goldsmith will be crewed by the Rutland Sailability charity, which provides training, support and equipment to enable people with disabilities to enjoy the challenge of sailing.

Andy Child, 54, who will be on board Gloriana tomorrow, is a former diplomatic and royalty protection officer who suffered life-changing injuries at the age of 31 after being brutally assaulted while on duty. Retired from the police on medical grounds, Child subsequently suffered further devastating injuries in a motorcycle crash. Though on crutches, he foiled a supermarket robbery 10 years ago. "Once a policeman, always a policeman," he said, adding that he was delighted to be part of the pageant, and that he had accepted the invitation "on behalf of all officers injured in the line of duty".

Across Britain hundreds of others will be testing their endurance during the lighting of a chain of 4,000 diamond jubilee beacons on Monday night. Breast cancer survivor Jo Lonsdale-Frith, 48, from Greater Manchester, will be climbing Scafell Pike in Cumbria as part of a Cancer Research UK fundraising squad lighting the beacon at the top of England's highest peak.

"My life turned upside down when I was diagnosed with breast cancer. But the treatment that followed, that was partly developed by Cancer Research UK, saved my life," she said. Joining her will be Nell McAndrew, the model and television personality who is the charity's ambassador. "My dad was treated for non-Hodgkin lymphoma in 2003, so the cause is close to my heart," said McAndrew, who, though she recently ran the London Marathon, but continued training for the beacon ascent "as climbing is quite different from endurance running".

Trekking to the top of Ben Nevis, Scotland's highest peak, Lt Col Mark Steed will be leading a team of military personnel in recovery, including three soldiers suffering from post traumatic stress disorder (PTSD), climbing with the Help for Heroes charity.

Steed, commanding officer of 51 Brigade personnel recovery unit, which looks after the recovery management of wounded, injured and sick personnel in Scotland, said: "All those we asked to take part were very enthusiastic. It is hugely important that we use opportunities like this to advertise what's being done." A Walking with the Wounded team will light the beacon atop Snowdon.

Northern Ireland is using the occasion to raise funds for a primary school in northern Uganda. The Fields of Life charity has attracted 300 climbers to scale Slieve Donard and light a beacon in the dramatic Mourne mountains. "The school is in Ongorono, a very impoverished area. Children have to pay 20 pence a month to go to school, and families can't even afford that," said Richard Spratt, the charity's chief executive.

"The beacon is an excellent idea to get people involved, and to do what we can."